Systems and methods herein generally relate to document security, and more specifically to copy identification provided with ultraviolet light exposure which reveals pantographs.
Pantographs are elements of the document that do not appear in the original, but do appear in a copy of the original. More specifically, complementary patterns are printed in the original. However, differences in these patterns are generally too small to seen by human without magnification, and therefore the different patterns simply appear as a shaded area of an original. When the original is copied, the scanner interprets these different patterns differently, which causes the patterns to be printed differently on the copy (e.g., metameric pairs of patterns), and this produces some form of pantograph or other mark on the copy that is easily seen by a human without magnification.